A javascript parser for the [HTML5 srcset] (http://www.w3.org/TR/html-srcset/) attribute, based on the [WHATWG reference algorithm] (https://html.spec.whatwg.org/multipage/embedded-content.html#parse-a-srcset-attribute). It has an extensive test suite based on the [W3C srcset conformance checker] (http://w3c-test.org/html/semantics/embedded-content/the-img-element/srcset/parse-a-srcset-attribute.html).
I’m on twitter @tweetywheaty.